科学记数法（英语：Scientific notation），又称为科学记号或科学记法，是一种记数的方法。

在科学记数法中，一个数被写成一个1与10之间的实数与一个10的次幂的积：

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Scientific notation (also referred to as standard form or standard index form) is a way of expressing numbers that are too big or too small to be conveniently written in decimal form. It is commonly used by scientists, mathematicians and engineers. On scientific calculators it is known as "SCI" display mode.